How to Make It
Heat 3 tablespoons of the olive oil in a large nonreactive saucepan. Add the onion and cook over moderately high heat, stirring, until softened, about 5 minutes. Add the tomato, garlic and chile and cook, stirring, for 5 minutes. Add the calabaza, Vegetable Stock and orange juice and bring to a boil. Reduce the heat to low, add 1 teaspoon salt and simmer until the calabaza is very soft, about 25 minutes.
Meanwhile, preheat the oven to 375°. On a baking sheet, drizzle the sliced Brazil nuts with the remaining 1 tablespoon olive oil. Bake for about 4 minutes, or until golden. Season with salt.
Using a slotted spoon, transfer 1 1/2 cups of the vegetables to a food processor or blender and puree until smooth. Stir the puree back into the soup and season with salt. Ladle the soup into shallow bowls and garnish with the sliced Brazil nuts.